Random encounter

A random encounter is a feature commonly used in hack and slash role-playing games and computer and video games whereby encounters with non-player character (NPC) enemies or other dangers occur sporadically and at random. In general, random encounters are used to simulate the challenges associated with being in a hazardous environment, such as a monster-infested wilderness or dungeon, but do not contribute significantly to the plot. For this reason, games that wish to introduce additional challenge and danger will use them; heavily plot-driven games use them more rarely. A specific comparative example would be between the early "Dragon Quest" and "Final Fantasy" games. The Final Fantasy series emphasize storyline, and therefore random encounters are relatively infrequent, whereas in the Dragon Quest series (more heavily inspired by 1980s-style RPGs) they are very common. Frequent random encounters are common in games like "Fallout" series or "Legend of Legaia".

Random encounters can add significant challenge to a game, but if they are overused, a game will be viewed as tedious. Continual fighting leads to increased player skill and higher character level, and eventually, the enemies and challenges become familiar and the challenge is compromised.

Role-playing games

Random encounters - sometimes called "wandering monsters" - were a feature of Dungeons & Dragons from its beginnings in the 1970s, and persist in that game and its offshoots to this day. Random encounters are usually determined by the gamemaster by rolling dice against a "random encounter table". The tables are usually based on terrain (and/or time/weather), and have a percentage chance for differing encounters with different numbers or types of creatures. Further modified by character tables, or other types of tables, which will determine whether the encounter is friendly, neutral or hostile. GMs are often encouraged to make their own tables, or modify results as they see fit. Specific adventures often have specific tables for micro-locations, like a temple's hallways.

Wandering monsters are often used to wear down player characters and force them to use up consumable resources, such as hit points, magic spells and healing potions. When used effectively, random encounters can improve the challenge for powerful characters. However, wandering monsters can also be used to compensate for poor game design - for example, when the Dungeon Master has not set up adequate challenges for the players as part of the main plot. When used abusively or punitively, random encounters are sometimes referred to derogatorily as "wandering damage".

Modern, plot-driven storytelling role-playing games do not generally use random encounters; rather, the gamemaster is supposed to decide when and where the player characters will encounter other game-world inhabitants depending on the needs of the plot.

Computer and video games

Computer and console RPGs have used random encounters since "Dragon Quest", "Final Fantasy", and "A Bard's Tale" in the mid-1980s, if not earlier. Random encounters happen when the player is traveling from one place in the game world to another (often through the use of a "world map" or overworld). Most often, the player encounters enemies (usually multiple) but sometimes also friendly or neutral characters, with whom the player might interact and possibly trade. Random encounters are, as the name implies, most often more or less random, but they can also vary in form and frequency depending on a number of factors, such as where the player is located in the game world and the statistics of the player character. In some games, items can be found to increase or decrease the frequency of random encounters, or even to eliminate them outright.

Random encounters usually occur more frequently in caves, forests and swamps than in open plains. The simplest sort of random encounter algorithm would be as follows:

# Each step, set X to a random integer between 0 and 99.
# If in plains, and X < 8, a random encounter occurs.
# If in swamp, desert, or forest, and X < 16, a random encounter occurs.

The problem with this algorithm is that random encounters occur "too" randomly for the tastes of most players, as there will be "droughts" and "floods" in their distribution. It's possible to have an encounter, take a step, and have another encounter, leading to the player's perception of getting "bogged down". A more elaborate random encounter algorithm (and similar to those used in many games) would be the following:

# Set X to a random integer between 64 and 255.
# For each step in plains, decrement X by 4. For each step in forest, swamp, or desert, decrement X by 8.
# When X &lt; 0, a fight ensues. Go to step 1.

This ensures that, in any terrain, the player will not experience more than one random enounter every eight steps. This is because random encounters in rapid succession are considered undesirable. The early games in the Dragon Quest series, for example, allow random encounters to occur one step after the other. (This is rare, but the algorithm is based on a random event each step, allowing for "droughts" and "floods" of random encounters.) A game with this type of system can sometimes be taken advantage of by initiating some action that will reset the counter (pausing, opening a menu, saving), especially when using an emulator. This is a popular trick in speedruns to skip time-consuming or dangerous battles, or it can be used conversely to ensure that each battle results in a rare or valuable encounter.

Random encounters have become less popular in video games with the passage of time, as gamers often complain that they are annoying or discouraging to exploration. The Final Fantasy and "Tales" series have abandoned random encounter systems with successive games, while relatively newer franchises such as the Chrono series and Kingdom Hearts have never used them.

A more commonly used tactic nowadays (used in "Final Fantasy XII", "Radiata Stories", "Fallout 1" and "2", "Legend of Legaia" and both "Kingdom Hearts" games) is to set a finite number of enemies in a given area. This cuts down on grinding and does not discourage exploration to the same extent.

The alternative to random encounters is spawning, where monsters always (re)appear at the same location.